402Signal

preview

Request-time catalog preflight over upstream catalogs plus a local shadow. Returns discovery_matches, displayed hits, claimed vs observed, not_probed:true. Does not probe and does not charge. Pay tools/call route for a live probe.

Input Schema

TableJSON Schema

Name	Required	Description
`need`	Yes	What to look up in the cache.
`networks`	No	Hard policy lock. Restricts searchable rails to this set. Unlike prefer_network, this is not a ranking preference.
`prefer_network`	No	Weak ranking preference only. Ranks this pay-in rail first but still searches and selects across all supported rails. Not a filter. Use networks for a hard policy lock.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`hits`	No
`need`	No
`total`	No
`cached_s`	No
`displayed`	No
`freshness`	No
`truncated`	No
`not_probed`	No
`miss_reason`	No
`discovery_via`	No
`discovery_matches`	No
`discovery_exhaustive`	No

TDQS

A4.3/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and does so well: it states preview does not probe, does not charge, and returns not_probed:true. It also names the output fields, making the behavior and side-effects visible to the agent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is four short sentences, each earning its place: operation, outputs, constraints, and the alternative for a live probe. It is front-loaded and contains no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description is complete for this tool: it explains what it returns, what it does not do, and where to go for a live probe. The output schema covers return-value structure, so the text does not need to repeat it. Only the validate sibling is unaddressed, but that is a minor gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all three parameters, including semantics for networks vs prefer_network. The description adds no additional per-parameter detail, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description specifies a concrete operation: a request-time catalog preflight over upstream catalogs plus a local shadow. It also distinguishes itself from route by explicitly saying it does not probe and does not charge, though it does not address the validate sibling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It clearly tells agents when to use an alternative: 'Pay tools/call route for a live probe.' The description also implies preview is the correct choice when no probe and no charge are desired. It does not provide an exhaustive when-to-use list or mention validate as an alternative.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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TDQS

A3.7/5.0

Disambiguation3/5

preview and validate both describe unpaid, non-charging preflight checks that report claimed vs observed, so an agent could initially confuse which one to call for catalog discovery versus SSRF validation. route is clearly distinct as the live, evidence-generating paid check.

Naming Consistency4/5

All tool names are lowercase single words, so the style is consistent and predictable. However, preview, route, and validate are terse and do not indicate their target resource or domain, making them less self-describing than a verb_noun convention.

Tool Count5/5

Three tools is well-scoped for this purpose: one for catalog preflight, one for live route verification, and one for URL/SSRF safety validation. Each tool covers a distinct stage without noticeable redundancy.

Completeness4/5

The set covers the key pre-spend workflow: preflight discovery, live route verification, and seller URL validation. Minor gaps exist, such as no tool to query the committed decision history or explicitly execute a payment, but the core verification surface is coherent.

Resources

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